Process for the production of ammonium chloride and alkali-metal sulphate



Patented July '5, 1927.

E fl; S T I OTTO GERNGROSS, OF GR'UNEWALD, NEAR BERLIN, GERMANY, ASSIGNOR TO FIRM CONTINENTAL!) AKTIENGESELLSCHAFT F'UR CHEMIE, OF BERLIN, GERMANY.

vPROCESS FOR THE PRODUCTION OF AMMONIUM CHLORIDE AND .ALKALI-METAL SULPHATE.

No Drawing. Application filed May 22, 1925, Serial No. 32,215, and in Germany June 11,1924.

The usual process for the production or ammonium chlorlde (sal ammonlac) by conversion of ammonium sulphate with sodium chloride in aqueous solution has the disad-' ployed and certain temperatures are malntained; the ammonium chloride (sal ammoniac) is sublimed from the mixture in pure state, and the principal inconveniences of the above mentionedproce'ss are avoided. Only when certain temperatures are applied however, is a pure white product obtained which, without further rectification, corresponds to marketable goods'of 96/100%. .The latter process has the disadvantage that the by-product which forms the residue in this process, i. e., sodiumor potassiumsulphate, has to be freed of the adhering impurities by re-crystallization, before it can be employed in the usual manner. This process is moreover tedious. v

The invention which will be hereinafter described, relates to a process in which the H inconveniences connected with the dig con- 86 version rocess are avoided and w ereby pure sub imated white sal ammoniac is obtained, the process being not limited to a predetermined temperature. Alkali-metal sulphate remains as residue, which, without re-crystallization, is adaptedto be employed in the usual manner. The process according to the present invention is based on heating a mixture of ammonium sulphate and alkalimetal chloride in the presence of gases, the dry conversion of the mixturethus being carried out in the presence of ases. Preferably gases which have an oxi izing action are used, such as oxygen or chlorine. For producing these gases small quantities of such substances may be addedto the said mixture during the dry conversion which, when heated will split off oxygen or chlorine, as for instance sodium peroxide, al-

This process will now be described by Way of example An intimate mixture of suitable quantities of ammonium sulphate with sodium chloride or potassium chloride and a small quantity of the above mentioned bodies which when being heated split off oxygen or chlorine, such as sodium peroxide, alkali metal nitrate, alkali metal chlorate, alkali metal persulphate, or the like, is-prepared. The mixture is then brought into the sublimation vessel and heated until the water containedin the common salt or the like escapes with sufiicient speed through the outflow pipeof the vessel. rapidly and strongly. Numerically expressed the process is as follows :-100 kg. of ammonium sulphate give with 77 kg. of sodium chloride and 3,7 kg. of sbdium chlorate an output of 75 kg. of pure white sal ammoniac and 100 kg. of calcinatedpure white glauber-salt (sodium sulphate). If to.

The mixture is then heated againthe above stated quantities of ammonium sulphate and sodium chloride 4 kg. of hypo-' chlorite or 3,2 kg. of alkali-metal nitrate or 3,3 kg. of persulphate'are added, an o utput of 75 kg. of sal ammoniac and 100 kg. of

glauber-salt is also obtained. The process is accelerated by in this process.

Having now particularly described and ascertained-the nature of my said invention, I declare that what I claim is .1. A dry process for the production of ammonium chloride and alkali metal sulthe oxidizing gases generated phate consisting in heating a mechanical mixture of ammonium sulphate and alkalimetal chloride in the resenceof gases, said gases being generated during said heating of said mixtures by adding an alkali-metal cbmpound thereto which when heated will split oil? such gases. I

2. A dry process for the production of ammonium chloride and alkali metal sulphate consisting in heating a mechanical mixture of ammonium sulphate and alkali metalehloride in the'presence of oxidizing gases, said oxidizing gases being generated during said heating of said mixtures by adding an a1kali-metal compound thereto which when heated will split off such gases.

A dry process'for the production of ammonium chloride and alkali metal sulphate consisting in heating a mechanical mixture of ammonium sulphate, alkali metal chloride and an alkali-metal compound which when heated will split off gases.

4. A dry process for the productionof ammonium chlorideand alkali metal sulphate consisting in heating a mechanical mixture ofammonium sulphate, alkali metal chloride and an alkali-metal compound which whenheated will split ofi' oxidizing gases.

'5. A dry process for the production of ammonium chloride and alkali metal sulphate consisting in heating a mechanical mixture of ammonium sulphate, alkali metal chloride and an .alkali-metal compound which when heated will split off oxygen.

6 A dry process for the production of ammonium chloride and alkali metal sulphate consisting in heating a mechanical mixture of ammonium sulphate and alkali metal chloride in the presence of alkali-metal chlorate.

In testimony whereof I have hereunto set my hand.

OTTO GERNGROSS. 

